Equations / Aboveground biomass
Native shrubs NZ (3 spp, Massey University): AGB from D and H (Table 7)
As printed (Table 7)
In this library's units, ready to compute (kg)
Aboveground biomass = 1.05 * exp(-3.57 + 2.18 * ln(DRC) + 0.4 * ln(H))DRC- Root collar / stem base diameter, cm
H- Total tree height, m
AGB is the sum of stem, branch and foliage dry biomass of the shrub. Natural log. D is the basal stem diameter over bark about 10 cm above ground (multi-stemmed shrubs: square root of the sum of stem diameters), mapped to DRC; H is total height in m. Table 7 reports adjusted R2 = 0.907 and RMSE = 0.288 (not used as r2 or rse). Shrubs had basal diameter up to 10 cm (mean D 3.4 to 3.8 cm by species, Table 4); the paper prints no D range for these models. The CF column is the factor the paper applies to back-transformed predictions.
doi:10.33494/nzjfs562026x567x · Open access · copy we read
CF = e(RSE²/2) Equation 2; Table 7 CF column 1.05
- Trees measured
- 19
- Correction factor
- 1.05 (applied)
- Method
- OLS regression on natural logarithms (power form), back-transformed with correction factor CF = exp(RSE^2/2)
- Where
- Massey University natural reserves and Dairy4 farm trial site, Manawatu
- Last checked
- 2026-11-02
On every build, the library's form and the paper's own form (in its units) must both give these values within 1%.
| Inputs | Expected | We get | From |
|---|---|---|---|
| DRC = 2, H = 1 | 0.134 | 0.134 | Computed from the printed form computed from the published form (a is ln(a), CF applied, coefficients as printed) |
| DRC = 4, H = 2 | 0.801 | 0.801 | Computed from the printed form computed from the published form (a is ln(a), CF applied, coefficients as printed) |
| DRC = 8, H = 3 | 4.27 | 4.27 | Computed from the printed form computed from the published form (a is ln(a), CF applied, coefficients as printed) |
Related
- Native shrubs NZ (3 spp, all sites): AGB from D (Table 7) · Wangui et al. 2026 · Root collar diameter
- Coprosma robusta (all sites): AGB from D and H (Table 7) · same paper · Aboveground biomass
- Coprosma robusta (Massey University): AGB from D and H (Table 7) · same paper · Aboveground biomass
- Native shrubs NZ (3 spp, all sites): AGB from D (Table 7) · same paper · Aboveground biomass
- Melicytus ramiflorus (Limestone Downs): AGB from D (Table 7) · same paper · Aboveground biomass
- Pittosporum crassifolium (Massey University): AGB from D and H (Table 7) · same paper · Aboveground biomass